Article packaging machines that arrange articles, such as food and beverage cans and bottles, into groups of desired sizes and configurations, and place those article groups into paperboard or corrugated board cartons, are well known. In some types of packaging machines, the packaging operations may be performed simultaneously, while in others they may be performed sequentially, enabling the packaging of article groups into cartons at rates of hundreds of cartons per minute. It is not uncommon, for example, for packaging machines to operate at production rates of two hundred cartons per minute to three hundred cartons per minute, and higher. Packaging machines utilize a variety of techniques to group articles to be packaged depending generally on the type of machine and the kind of carton used. Some machines, for instance, place articles into a sleeve-type carton, usually by forming the sleeve from a carton blank, grouping the articles, and pushing or sliding each group of articles into an open sleeve, which is then closed at each end. Other machines may place basket-type cartons over an article group, and then close the carton along its bottom side to complete the packaging operation. Still other machines may form articles into groups, and then wrap a paperboard carton blank around each group of articles to form a completed package. These wrap-type cartons can include features that allow the opposed ends of the carton to cooperate to form a locking mechanism that holds the wrap-type carton together around each group of articles. Glue or other chemicals can be used to bind carton surfaces to one another in any type of carton, either alone or in conjunction with mechanical carton locking features, such as tabs and slots.
When packaging articles such as soft drink and beer cans into cartons, it sometimes is desirable to group the articles in two layers within the carton, with an upper layer of upright articles overlying a lower layer of upright articles. It is common to separate the layers with a paperboard divider pad on which the upper layer rests. Such a packaging configuration is sometimes referred to as “twin layer packaging.” Packaging machines for obtaining twin layer packaging of articles are known, one such machine being exemplified in U.S. Pat. No. 5,758,474 of Ziegler, which is commonly owned by the assignee of the present application and hereby incorporated fully by reference. Such packaging machines generally may comprise an infeed assembly that progressively directs articles in groups into the selector bays of a synchronously moving selector flight. The infeed assembly includes an upstream infeed belt and associated infeed lanes for directing the bottom layer of articles into the bays. A separate downstream infeed belt and associated infeed lanes, which may be disposed at an elevated level relative to the upstream infeed belt and lanes, progressively directs the top layer of articles into the selector bays atop the already loaded bottom layer of articles. The articles thus are staged in two overlying layers in the selector bays and subsequently are pushed with a pusher assembly, sometimes referred to as a “barrel loader,” into a waiting open carton on an adjacent and synchronously moving carton flight. The cartons are then closed to complete the packaging process.
Another example of a twin layer packaging machine is disclosed in pending U.S. patent application Ser. No. 12/487,261, also owned by the assignee of the present invention, the entire contents of which are hereby incorporated by reference. In this example, a lower layer of articles move from their infeed lanes into adjacent synchronously moving selector bays, which group them into a predetermined configuration. A fixed pusher rail then sweeps the lower layer of articles from the selector bays into aligned synchronously moving can bays, which frees the selector bays. A divider panel is placed atop the lower layer of articles in the can bays. An upper layer of articles are then moved from their infeed lanes into the freed selector bays, which, again, group the upper layer of articles into the same configuration as the lower layer of articles. The selector flight then ramps upwardly to an upper level, carrying the upper layers of articles upwardly to a position above the lower layers of articles in the can bays. Another fixed pusher rail then sweeps the elevated upper layer of articles into the adjacent can bays atop the lower layer of articles already staged therein. The articles are thus staged in twin layered groups within the can bays. Pusher rods of an adjacent pusher rod assembly or barrel loader then extend laterally to push the staged twin layer groups of articles into open cartons on an adjacent synchronously moving carton flight. The cartons are then closed to complete the packaging operation.
Barrel loaders of packaging machines such as those discussed above may take several forms. One type of barrel loader, exemplified in the aforementioned U.S. Pat. No. 5,758,474, generally comprises a pair of spaced apart chain flights that carry a plurality of loader arm assemblies. The loader arm assemblies are oriented transversely with respect to the downstream direction of the machine and are adjacent to and move in synchronization with selector bays or can bays (depending upon the type of twin layer packaging machine being used) containing grouped articles such as beverage cans. Open ended cartons move synchronously with the selector bays or can bays on the opposite side from the barrel loader. The loader arm assemblies include loader arms that are extendable on rods in a transverse direction toward the selector bays or can bays and the open cartons on their opposite sides. The loader arms have cam followers and the barrel loader includes cam surfaces that are angled with respect to the downstream direction of the packaging machine. As the loader arm assemblies are moved in a downstream direction by their chain flights, the cam followers of the loader arms engage the angled cam surfaces, which cause the loader arms to extend transversely. The loader arms have loader faces on their ends that are sized and configured to engage a group of cans or bottles in a selector bay or a can bay as the loader arm extends to push the group progressively from the selector bay or can bay into waiting open carton sleeves. When a loader arm is fully extended and has completed the transfer, retraction of the arm is initiated and it is carried around to the bottom flight of the chain, where its cam follower engages another angled cam surface to retract the loader arm to its home position as it moves back to the upstream end of the barrel loader for the next cycle.
A problem with prior art barrel loaders has been that they have not been easily changed over to be able to load articles such as beverage cans of different sizes, and/or different numbers or configurations. Such a change-over generally has required that the packaging machine be shut down, that current loader faces be removed from the loader arms, and that different loader faces configured for the new container size and/or configuration be attached to the loader arms. Alternatively, an array of attachments and/or extenders may attach to the loader faces to reconfigure the faces for a different container configuration. This process is time consuming, results in excessive machine down time, and is subject to human error. There exists a need for an improved barrel loader that overcomes these and other problems and it is to the provision of such a barrel loader, and a packaging machine including such a barrel loader, that the present disclosure is primarily directed.